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ARS Home » Northeast Area » Geneva, New York » Grape Genetics Research Unit (GGRU) » Research » Publications at this Location » Publication #428883
Research Project: Genetic Improvement of Grape Quality and Adaptation to Diseases and Abiotic Stress

Location: Grape Genetics Research Unit (GGRU)

Title: First brassinosteroid-based dwarf mutant discovered and characterized in grapevine

Author
item Yang, Yingzhen
item ZHOU, CHENG - Cornell University
item ORAVEC, MADELINE - Cornell University
item REISCH, BRUCE - Cornell University
item Zhong, Gan-Yuan

Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/23/2026
Publication Date: 5/4/2026
Citation: Yang, Y., Zhou, C., Oravec, M., Reisch, B., Zhong, G. 2026. First brassinosteroid-based dwarf mutant discovered and characterized in grapevine . Theoretical and Applied Genetics. 139:147. https://doi.org/10.1007/s00122-026-05225-6.
DOI: https://doi.org/10.1007/s00122-026-05225-6

Interpretive Summary: Grape production is a complex and challenging process that requires careful management of cultural and environmental factors, often by hand. These factors could be minimized or potentially even eliminated by selective breeding to make grape cultivars more amenable to mechanization. Reducing overall plant size is a key step in developing such grape cultivars and could be potentially realized by leveraging dwarfism. In this study we discovered and characterized a natural dwarf vine and demonstrated the possibility of creating similar dwarf vines through gene editing. This work provides an important step in leveraging a dwarf gene to develop new grapevine cultivars with altered plant architecture for enhancing grape yield and mechanization-based production efficiency. The knowledge reported here may also benefit other woody fruit species, such as apples, in which dwarfing rootstocks and scions are highly desirable.

Technical Abstract: In this study, we investigated the genetic control of dwarfism in natural dwarf mutant lines of grapevines. Through trait segregation and marker-trait association analyses, we identified a major locus on Chromosome 14 tightly associated with the dwarf trait. Subsequently we conducted a bulked RNA-seq analysis, fine mapped the dwarf trait, and identified VvBR6OX1, a cytochrome P450 enzyme involved in brassinosteroid synthesis, as a candidate gene for the observed dwarfism. RNA-seq sequence analyses revealed the presence of two in-frame deletions in the gene, a 12-bp deletion in exon 1 and a 9-bp deletion in exon 4, and a survey of the two indels in Vitis germplasm suggested that the 9-bp deletion was likely the cause of dwarfism in the mutant. We recreated similar dwarf grapevines by knocking out VvBR6OX1 through gene editing and confirmed VvBR6OX1’s role in controlling vine architecture. Additionally, we observed several extremely compact dwarf vines and determined that the compact dwarfing phenotype was a result of simultaneous editing of a second BR6OX gene, VvBR6OX2. The discovery of a BR-related dwarfism in grapevine provides an important genetic avenue for improving vine architecture with potential for higher-density planting, reduced labor needs and adaptability to mechanization in grape production.